Human Subsistence and Climate Change in the Late Pleistocene of North-western Africa: Insights from Plant Macrofossils at Ifri El Baroud, Morocco (c. 23–12 ka cal BP)

Abstract

This paper explores how plant use among Iberomaurusian groups from north-western Africa adapted to the rapid climate changes of the Late Pleistocene. To achieve this, we analyse archaeological seeds and fruit remains from the site of Ifri El Baroud, Morocco (c. 23–13 ka cal BP), which provides high-resolution and well-contextualised data to assess changes and continuity in plant exploitation over approximately 10,000 years. A total of nine taxa that could be used as food have been identified. Wild legumes, including vetch (Lathyrus/Vicia spp.) and wild lentil (Vicia lens subsp. lamottei), are the most frequent. Other taxa identified include juniper (Juniperus sp.), ephedra (Ephedra sp.), acorns (Quercus sp.), elderberry (Sambucus nigra), lentisk (Pistacia lentiscus), grasses (Poaceae), and geophytes. Results indicate that between c. 23 and 16 ka cal BP, during the cold and arid conditions of Greenland Stadial 2.1, plant gathering focused on a small number of annual plants and shrubs. After c. 15.5 ka cal BP, the wetter and warmer conditions of Greenland Interstadial 1 allowed for an increase in the number of plant taxa collected. We argue that the improvement in climatic conditions after c. 15 ka cal BP led to an intensification of plant exploitation through improved processing methods (use of fire, stone boiling, storage), which enabled the consumption of previously underutilised plants and enhanced nutrient extraction from foods already in use. We suggest that this shift in the exploitation of plant resources may have allowed Late Iberomaurusian people to occupy settlements for longer periods and develop a semi-sedentary lifestyle.